Swimming fin



L. MARES Jan. 21, 1969 SWIMMING FIN Filed Sept; 7, 1967 s E R I M W 0 c w M o D 0 ATTORNEYS United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE A swimming fin comprising a shoe adapted to be worn on the foot and a web extending forwardly from the toe end of said shoe. In said web at least one flap is formed, directed in the same direction as said web and flexible in both directions from the web plane.

The present invention relates to swimming fins made of resilient material, such as rubber or rubber-like plastic material, of the kind comprising a shoe section, and a web extending forwardly from the toe end of said shoe.

In the fins of this type, the web of the fin is flexed while swimming substantially only in its front end part, while the intermediate part and/or the rear part of the web are substantially stiff. Therefore, in the known fins, only the flexible front part of the web substantially contributes to the swimmers propulsion, while the intermediate and/or rear parts of the web, constituting the main fraction of the web area, do not contribute, or contribute only up to a limited extent, to the swimmers propulsion.

It is accordingly the main object of the present invention to provide a swimming fin of the kind set forth, in which the intermediate and/or rear parts of the web of the fin contribute to a greater extent and in a new and more efficient manner to determine the propulsion effect.

To this purpose, according to the invention, one or more flaps are formed in the intermediate and/or rear parts of the fin web. The said flaps are substantially directed in the same direction as the main web and are elastically flexible in both directions with respect to the fin web plane.

In this way, while swimming, and both during the upward stroke and the downward stroke of the fin, the said flaps automatically and elastically bend in the same direction as the flexible front part of the web, thus providing a supplementary propelling push, in addition to the main push provided by the inflected front part of the web.

These and other features of the invention, as well as the advantages deriving from it will be apparent from the following specification of a preferred embodiment of the invention, shown by way of non-limiting example in the accompanying drawing, in which:

FIG. 1 is a plan view of a fin according to the invention.

FIG. 2 is a perspective top view of the same fin with the main web and the small flaps flexed downwardly.

FIG. 3 is a bottom perspective view of the fin with the main web and the flaps flexed upwardly.

Referring to the drawing, the swimming fin shown comprises a shoe 1 and a web 2 made integral with said shoe 1 and extending forwardly therefrom.

The shoe 1 and the web 2 are made of resilient material, such as rubber or plastic.

In the web 2, two sidewise arranged flaps 4 are formed by means of cuts 3. Said flaps 4 are directed in the same direction as the web 2, and are integrally connected at their rear ends to the web 2. The web 2, as well as the ice flaps 4, are provided with longitudinal stiffening ribs 102, respectively, 104, which are formed on the top and on the bottom sides of web 2 and flaps 4, respectively. As shown in the drawings, these longitudinal ribs become progressively of reduced cross-section towards the front part of web 2 and flaps 4 until their front ends completely merge into the web, while the rear ends are connected to the toe end of shoe 1.

The mode of operation of the just described swimming fin will be evident upon consideration of FIGURES 2 and 3 of the drawings.

While swimming, and for example during the upward stroke of the fin, both the front part of the web 2 and the flaps 4 bend downwardly under the pressure of water, as shown in FIG. 2. In this way, the flaps 4 bend clear of the'respective openings 5 in the Web 2 and therefore permit the passage of water through this substantially stiflf part of the web 2. At the same time, the inflected flaps 4 come to form inclined surfaces which determine a supplementary propelling push, analogous to, and concordant with, the push provided by the inflected front part of the web 2. During the fins downward stroke, the web 2 and the auxiliary flaps 4, are bending upwardly, as shown in FIG. 3, determining an analogous increased propulsion push due to the combined effect of the inclined surfaces of front end of web 2 and of flaps 4, thus sensibly increasing the efficiency of the fin. The fin according to the invention can be considered as formed by a web 2 and two flaps 4 which all individually and elastically bend in the same directions while swimming.

I claim:

1. A swimming fin adapted to assist in propelling a swimmer through the water and comprising a shoe part and a longitudinally extending web part formed of a resilient material, said sh-oe part adapted to be worn on the foot of a swimmer and having a toe end, said web part secured to said shoe part and extending forwardly from the toe end thereof, said web part having an upper surface and a lower surface, said web part having a front section spaced forwardly from the toe end of said shoe part and a rear section extending between and securing said front section to said shoe part, said front section being flexed relative to said shoe part when said web part is used in swimming while said rear section remains substantially rigid relative to said shoe part, longitudinally extending ribs formed on said web part and extending forwardly from said shoe part and said web part extend ing transversely therebetween, an opening in said web part spaced forwardly of said shoe part and a flap coextensive with said opening and formed from the material forming said web part, said flap integrally connected to the rear section of said web part and the remaining periphery of said flap extending forwardly from the portion integrally secured to said web part being separated from said web part and being free to flex about its portion secured to said web part upwardly from the upper surface and downwardly from the lower surface of the rear section of said web part for assisting in propelling a swimmer.

2. A swimming fin as set forth in claim 1, wherein said ribs comprise a pair of spaced ribs extending along the longitudinally extending edges of said web part and at least one longitudinally extending intermediate rib spaced between said edge ribs for dividing the said web part into at least two said web areas, and each said web area containing one of said flaps in the rear section thereof.

3. A swimming fin as set forth in claim 2, wherein a rib is formed in each of said flaps and extends therefrom to said shoe part.

4. A swimming fin as set forth in claim 3, wherein said ribs have a cross sectional area which is at a maximum area at the point of attachment of said ribs to said 3 4 shoe part and the cross sectional area of said ribs dimin- FOREIGN PATENTS ishes as the ribs extend forwardly from said shoe part. 444,567 1/1949 Italy.

References Cited 1,407,570 6/1965 France.

UNITED STATES PATENTS 5 MILTON BUCHLER, Primary Examiner.

3,055,025 9/1962 Ferrard et a1. 9309 3,183,529 5/1965 Beuchat 9309 J. PITTENGER, Assistant Examiner. 

